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Does anyone know what the safe flywheel horsepower limit is on the 4.6 3 valve engine? I have been told that its 500 hp.
 

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I dont know fly wheel but i thought to the tires its around 600 with forged internals. idk about stock though, im pushing 452 on ten pounds of boost with stock internals
 

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On stock internals I wouldn't go over 475rwhp on a Dynojet dyno. I talked to a guy who had 525 on a mustang dyno and it only lasted 3000 miles. That's also going to depend on how much time you spend at the upper end of the RPM range..:shigrin
 

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I have heard that 450RWHP is pretty safe with a good tune. I have been investigating this also.
 

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mine broke at 440 @ around 4k miles...
 

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A lot of it depends on the tune its self. I was at 421rwhp for a long time and got it bump to 447rwhp/425tq about 4 or 5 months ago. But my tune Adam with ST Motorsports told me that's it till you get the motor built. So 450 it a safe zone so to speak. There's no real safe zone either, but I would stay less than 450rwhp.
I've been running the 421rwhp for years and haven't had any problems with the 447rwhp either. My trans is broke again (TC) and soon to be built better than ever.
 

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Don't forget about TQ numbers. TQ is what usually break engines. I car making 400rwhp and 550 rwtq is playing with the devil.
 

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Usually a good mark is what ever you can put to the wheels with 10lbs of boost. Normally it's boost that kills our motors (on an F/I car). That 10lbs will result in a rwhp in the range of 420 to 480 (most hit near that 450 mark mentioned). It just depends on what F/I you are using and what supporting mods you have (LT Headers, cams, etc.).

Hope that helps.
 

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Good thread, was just thinking about this myself. Yea, it seems 450 wheel and 10 pounds of boost (with a GOOD tune) is the limit for decent reliability for stock internals.

With built motor, I've seen a couple of Stangs belching out 700+ to the ground.. One here with Nitrous serving up 900+ whp I think.. Can't remember his name, bad.. I know.

Build your engine right and 600 whp is nothing.
 

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A lot of it depends on the tune its self. I was at 421rwhp for a long time and got it bump to 447rwhp/425tq about 4 or 5 months ago. But my tune Adam with ST Motorsports told me that's it till you get the motor built. So 450 it a safe zone so to speak. There's no real safe zone either, but I would stay less than 450rwhp.
I've been running the 421rwhp for years and haven't had any problems with the 447rwhp either. My trans is broke again (TC) and soon to be built better than ever.
What pulley were you using to get 421?
 

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Ford warrants 400 bhp so a few more should be safe.
 

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Ford warrants 400 bhp so a few more should be safe.
Are you saying Ford warranties 400hp? If so that is incorrect. Ford will allow you to put the FFRP Whipple on a 3v and will still honor your warranty but that kit makes more like 380 at the wheels. And you have to use their tune. Secondly Ford does not warranty HP#'s, they warranty their FFRP blower/tune combo.

No one is going to be able to walk into a Ford service department with a hole in a piston and a KB blower stiitig on it and get Ford to pay for the repair.

From what I understand bouncing off of the rev limiter (which is horribly abrupt) while under boost (power) is the #1 reason for broken bottom ends (I said broken, not melted down;)).

Banging into the rev limiter under power causes all sorts of unusual and mis-timed engine vibration/harmonics which breaks parts. The rods are the weakest lik so they are the first thig to fail.
 

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mine broke at 440 @ around 4k miles...
Unless it dropped a valve (which I doubt) that looks like a lean and or a timing issue. I would define that as being “melted down” opposed to broken. If that were the case the HP level doesn't have much to do with it.
 

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Are you saying Ford warranties 400hp?
I am going by what Ford's warranty says for Ford Racing parts. They will give a full 36/36000 if the parts are installed at time of purchase that bring HP up to 400, FR 400 HP Super Pack, and is dealer installed; 12/12000 if installed later.
Now with warranty when Ford Dealer installed.
Part No. M-6066-M463V7 Black
Part No. M-6066-M463P7 Polished

There is no warranty on FR 500 HP Super Pack
Part No. M-6066-M117 Black
Part No. M-6066-M11P7 Polished.

I ass/u/me it would also void the power train warranty.
Ford Racing Limited Warranty. When installed by a Ford, Lincoln or Mercury Dealer,
(“Ford”) warrants specific Ford Racing Performance parts identified herein M-6066-M463V7, M-6066-M463P7,... found to be defective
in factory-supplied material or workmanship for 3 years/36,000 miles (whichever comes
first) when installed on a new vehicle at the time of vehicle sale or 12 months/12,000 miles
(whichever occurs first) when installed after the date of vehicle sale but prior to the expiration
of the 3 years/36,000 miles coverage (whichever occurs first) under the New Vehicle Limited
Warranty. This warranty is valid for the original owner of the vehicle and is transferable to
any other party. Proof of purchase is registered by the installing dealer by contacting the
Ford Racing Call Center at 1(800) 367-3788.
 

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I am going by what Ford's warranty says for Ford Racing parts. They will give a full 36/36000 if the parts are installed at time of purchase that bring HP up to 400,
Yeah, but the kit doesn't make anywhere near 400. It's not your fult the catalog lied to you.

FR 400 HP Super Pack, and is dealer installed; 12/12000 if installed later.
Now with warranty when Ford Dealer installed.
Part No. M-6066-M463V7 Black
Part No. M-6066-M463P7 Polished

I ass/u/me it would also void the power train warranty.
Not unless the dealer was a buch of A holes.

Well I guess we are arguing semantics then.

Ford DOES NOT warrant 400hp at the wheels which as far as I am concerned is the only way to rate power. Their claims are based on the motor being on a dyno stand, in a dyno cell with everything perfect. The information you just posted confirms that. They warrant part numbers……….:

Part No. M-6066-M463V7 Black
Part No. M-6066-M463P7 Polished

………….which are for kits that don’t make 400hp, they make 380 on a good day. Standard optimistic manufacturer claims, applies for everything from lawnmowers to Lamborghinis (there is a trivia joke in there, can you get it). And if you got that kit to make 400hp through tuning/pulley change then that would void the warranty on that part. They warranty what comes in the box, nothing else.

In conclusion, I agree, they do warranty those kits. But they don’t warranty 400hp, let alone 399. But we are arguing semantics. The only reason I said something is that the less educated buyers may take what you said and ran with it all the while being wrong. It would go something like this:

“Mr. Service manager, my motor let go with the FRPP blower and I need you to fix it under warranty”. The service manager opens the hood and sees a completely different intake, full length headers, coils and then when they check the tune and find out its custom. You would get to hear Mr. Service Manage say “I’m sorry sir, Ford doesn’t cover warranties on modded FRPP blower setups and alternate fuel mapping”.

They dumbed down that blower quite a bit so they could offer a warranty. It’s just like the 03-04 Cobras. They had a warranty, but for Ford to be able to cover them they made very little boost, almost no timing and ran pig rich.

They don’t cover 400hp, they don’t cover a few extra mods, I got that info off of your site. There is no mention of other parts or part numbers in there….unless I am going blind

“Ford Racing Limited Warranty. When installed by a Ford, Lincoln or Mercury Dealer,
(“Ford”) warrants specific Ford Racing Performance parts identified herein M-6066-M463V7, M-6066-M463P7,... foundto be defective in factory-supplied material or workmanship for 3 years/36,000 miles (whichever comes first) when installed on a new vehicle at the time of vehicle sale or 12 months/12,000 miles (whichever occurs first) when installed after the date of vehicle sale but prior to the expiration
of the 3 years/36,000 miles coverage (whichever occurs first) under the New Vehicle Limited Warranty. This warranty is valid for the original owner of the vehicle and is transferable to any other party. Proof of purchase is registered by the installing dealer by contacting the FordRacingCallCenter at 1(800) 367-3788.”
 

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Yeah, but the kit doesn't make anywhere near 400. It's not your fult the catalog lied to you.


They don’t cover 400hp, they don’t cover a few extra mods, I got that info off of your site. There is no mention of other parts or part numbers in there….unless I am going blind
I meant bhp as Ford does. So whatever 500 bhp is over Fords limit I ass/u/me.

I cut out all but the two parts I was talking about.
This is the catalog link.
Ford Racing Performance Parts [Ford Racing Parts Catalogs]
 

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I broke a few pistons at 444 RWHP on my turbo set-up @9psi :shigrin
It´s just random which motor will give in and who last´s in my opinion....tic tac tic tac.
If you want to be safe then don´t go above 5psi with the Roushcharger (keeps the Ford warranty) . Or maybe find another guy with a FI stang with proven 30k miles+ and completely copy his setup and tune if you want to push it higher. I know a few guys here in Iceland "running" 10psi on stock internals, only one of them with a Whipple who´s a regular at the strip trapping mid to high 11´s.
The other guys are tuned at 10psi mostly for show and no go and hardly ever push their cars or drive them for that matter, just flash some dyno sheet´s and keep theirs parked in the garage with 1-5k miles on it. At least from what I´ve been reading on the forums it´s a 50/50 chance you´ll need a new block if you go over 440rwhp.....maybe it will last, but for how many miles ?
 
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